If you're in a place that wants to host it, it's fairly easy to get enough local support. When we did it here in Cincinnati, once we made it known we were making a bid, a lot of people stepped up with offers of help. Once we actually won the bid, people came out of the woodwork to help! The local Convention and Visitors Bureau was also a big help.
I think the tough part is finding a hotel. It has to be pretty darn big to handle the size we're grown to, with plenty of meeting space. At it's 2010 size, there is no longer a hotel in Cincinnati big enough to host, and we had it here only a few years ago (2008). The even harder part is finding a place willing to allow outside alcohol. For most hotels, that's a total non-starter. When getting bids here, one banquet manager essentially threw us out. Another made a bid, and then corporate made them retract it. No outside-alcohol events at all for Hilton.